feat: implement (From|To)Json for more @immut/*.T types

[rami3l]

This pull request introduces JSON (de)serialization functionality to various immutable data structures (list, sorted_map, and sorted_set). The changes include implementing the (From|To)Json traits for these structures, adding corresponding methods, and updating the test cases to validate the new functionality.

As previously discussed with @bobzhang.

[peter-jerry-ye-code-review]

The provided git diff output reveals several changes and additions across multiple files within a project, particularly focusing on adding JSON serialization and deserialization capabilities for various data structures. Here are three key observations and suggestions based on the changes:

1. Potential Bug in JSON Deserialization for Sorted Set (immut/sorted_set/types.mbt):

   • The line +} derive(Default) suggests that the Default trait is derived for the T enum, which represents a sorted set. However, the commit message does not indicate why Eq was removed. Deriving Default for an enum typically requires a default variant (e.g., Empty), but it's crucial to ensure that all operations involving this type correctly handle the default case, especially in deserialization logic where incomplete data might lead to unexpected behavior.
   • Suggestion: Review the deserialization logic to ensure it properly handles the Default case and verify why Eq was removed. If Eq is still needed, consider re-adding it.

2. Potential Typo in JSON Deserialization Error Message (immut/list/list.mbt):

   • The error message "@immut/list.from_json: expected array" seems correct, but it's always good to double-check error messages for typos or unclear language.
   • Suggestion: Ensure the error message is clear and concise. If possible, include more context or the expected JSON structure to aid debugging.

3. Incomplete Documentation for New JSON Functions:

   • Several new functions for JSON serialization (to_json) and deserialization (from_json) are added across multiple files, but the commit does not include updates to the documentation comments for these new functions.
   • Suggestion: Update the doc comments for each new to_json and from_json function, providing examples and explaining the expected input and output formats. This will greatly assist users in understanding how to use these functions correctly.

These observations focus on potential issues that could affect the robustness and usability of the code, particularly around the new JSON handling capabilities. Addressing these points will help ensure the code is both reliable and user-friendly.

[coveralls]

Pull Request Test Coverage Report for Build 3625

Details

• 37 of 44 (84.09%) changed or added relevant lines in 4 files are covered.
• 5 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.4%) to 82.688%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
immut/sorted_set/generic.mbt	12	13	92.31%
immut/list/list.mbt	9	11	81.82%
immut/sorted_map/utils.mbt	8	10	80.0%
immut/sorted_set/immutable_set.mbt	8	10	80.0%

Files with Coverage Reduction	New Missed Lines	%
immut/sorted_set/immutable_set.mbt	5	89.42%

Totals
Change from base Build 3616:	0.4%
Covered Lines:	4251
Relevant Lines:	5141

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💛 - Coveralls